Method of manufacturing full-color organic electro-luminescent device

ABSTRACT

A method of manufacturing a full-color organic electro-luminescent device on an indium-tin-oxide glass substrate. A pattern is formed on the indium-tin-oxide glass substrate by the photolithography and the etching process. The indium-tin-oxide glass substrate is cleaned. An insulation pad is formed over the indium-tin-oxide glass substrate. A low shadow mask and a high shadow mask are sequentially formed over the insulation pad by conducting dry film photo-resist processes. A hole-transport layer is formed over the indium-tin-oxide glass substrate by conducting a vapor-depositing process. Three vapor-depositing processes are simultaneously conducted to form red, green and blue light-emitting layers on the hole-transport layer using the low shadow mask and the high shadow mask as a barrier. An electron-transport layer and a metal layer are serially formed over the light-emitting layers by conducting vapor-depositing processes.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority benefit of Taiwanapplication serial no. 89115831, filed Aug. 7, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of Invention

[0003] The present invention relates to a method of manufacturing afull-color organic electro-luminescent (OEL) device. More particularly,the present invention relates to a method of manufacturing a full-colororganic electro-luminescent (OEL) device using a special designedprocess and equipment, in which the dry-film photo-resist as the shadowmask is made on the insulated pad and the deposition of RGB sub-pixelsis carried out in the same time.

[0004] 2. Description of Related Art

[0005] Investigation of on organic electro-luminescent material began inthe 1960s and more than 30 years of research data has been accumulatedright now. When the investigation of single crystal organic compound wasfirst reported in 1963, a high voltage of around 400 volts had to beapplied before luminescent occurs. Yet, the brightness level produced bythe luminescent material is too weak to have any real-life application.

[0006] In 1987, Kodak in America reported some success in producingorganic low-molecular-weight electro-luminescent device in Appl. Phys.Lett., Vol.51, p914(1987). In 1990, Cambridge University in England wassimilarly successful in utilizing the polymer material to produceelectro-luminescent devices in Nature, Vol.347, p539 (1990). From theseearlier researches, foundation for investigating actual application ofelectro-luminescent devices by governments, institutes and academies islaid.

[0007] Highly desirable properties of electro-luminescent materialinclude self-illumination, wide viewing angle (up to 160°), rapidresponse, low driving voltage and full-color spectrum. Hence,electro-luminescent been highly regarded as the planar displaytechniques of the future. At present, the development ofelectro-luminescent devices has reached such a high degree ofsophistication that electro-luminescent display can be out in the nextgeneration of planar color displays. These planar luminescent devicescan be used in high-quality, full-color planar displays such asminiature display panel, outdoor display panel, computer and televisionscreens.

[0008] At present, research in electro-luminescent products is directedtowards the investigation of device and material structure. Rapiddevelopment in low-molecular-weight electro-luminescent material hasproduced the first prototype full-color organic electro-luminescentdisplay. However, some technical problems still prevent the use polymermaterial in full-color organic electro-luminescent devices. One majordifficulty lies in the alignment of red-green-blue (R-G-B) sub-pixels inthe spin-coating process.

[0009] Color display techniques using organic electro-luminescentmaterial can be roughly divided into two sub-categories, namely, directfull-color display techniques and indirect full-color displaytechniques.

[0010] Literature of direct full-color display techniques includes:

[0011] 1. A full-color electro-luminescent device structure havingmicro-cavities of various depths is developed in Cambridge (Adv. Mater.,Vol.7, p541 (1996); Synth. Met., Vol. 76, p137(1996)), by Cimrova et. el(Appl. Phys. Lett., Vol. 69, p608 (1996)); in Bell Lab and Motorola(R.O.C patent no. 301,802, 318,284, 318,966). However, the method ofproduction is rather complicated. Furthermore, producing micro-cavitiesat different depth levels is a high-cost process.

[0012] 2. A method of stacking organic electro-luminescent elementcapable of emitting blue light and organic electro-luminescent elementcapable of emitting red light on top of a substrate is developed jointlyby Princeton and Southern California University (Appl. Phys. Lett.,Vol.69, p2959 (1996)); R.O.C. patent no. 294,842). However, the methoduses difficult fabrication techniques. Moreover, the metal electrodesbetween the light-emitting element blocks off a portion of the red andgreen light, thereby lowering the brightness level.

[0013] 3. A method that uses X-Y addressing pattern for fabricating afull-color organic electro-luminescent device capable of different colorpixels is developed by Kodak Co. of America (U.S. Pat. Nos. 5,294,869and 5,294,870). It utilizes the shift of metal mask to form R-G-Bindividual sub-pixels in the deposition process so that it is not goodfor the applications of higher resolution and larger substrate.

[0014] 4. A method of fabricating full-color organic electro-luminescentdevice by photo bleaching is developed by professor Kido of Japan. Themethod uses light to damage the resonance structure of red-energy-gapmaterial of the light-emitting layer so that energy gap of the materialis increased, green-blue-red pixels are formed and pixels of differentcolors are fixed for full-color display.

[0015] Besides the aforementioned production methods, a method thatutilizes an ink-jet printing technique instead of spin-coating tofabricate a polymer electro-luminescent device is developed by Yang Yang(Science, Vol.279, p1135(1990)). The method can reduce the consumptionof polymer material and can produce whatever display pattern and words.Size of ink drop can be as small as 30 μm. The method can be applied toproduce a full-color display device. However, this method is new andmany technical problems still exists. Problems such as thetransportation of indium-tin oxide glass, the type of solvents to beused and the blocking of inkjet nozzle need to be addressed.

[0016] Literature of indirect full-color display techniques includes:

[0017] 1. TDK Co. has developed a full-color organic electro-luminescentdevice that uses a color filter. First, a conventional method is used tofabricate a white light electro-luminescent component. Red, green andblue color filters are added to the white-light-emitting pixels so thatthe white light is converted into red, green and blue lightrespectively. Although this method is capable of producing a full-colordisplay device from a white-light-emitting component, the filtersgreatly reduce light intensity of the device.

[0018] 2. A full-color organic electro-luminescent device having a colorconversion layer has been developed by Idemitsu Kosan. The device has astructure similar to a light-emitting device with filters. Althoughlight conversion of the blue light can be used to produce a full-colordisplay device, the process of forming separating column is complicated.Moreover, using a conversion layer for red, green and blue will lowerlight intensity of the device.

[0019] Apart from the previous methods, another direct full-colordisplay technique similar to this invention is presented and compared asbelow.

[0020] Kodak of America has introduced an X-Y address-patterning methodfor producing a full-color organic electro-luminescent device in U.S.Pat. No. 5,294,869. FIGS. 1A through 1E are schematic cross-sectionalviews showing the steps for producing a full-color organicelectro-luminescent device according to a conventional X-Y addressingpattern. First, as shown in FIG. 1A, a vertical shadow mask is formedover an indium-tin-oxide glass substrate 100 by a wet photo-resistproduction or a dielectric film deposition method. As shown in FIG. 1Bto FIG. 1D, three vapor deposition operations are carried out to depositred, green and blue color materials. In the first vapor depositionoperation 104 shown in FIG. 1B, a first type of material is deposited onthe substrate 100 at an angle θ₁ to form a sub-pixel 106. In the secondvapor deposition operation 108 as shown in FIG. 1C, a second type ofmaterial is deposited on the substrate 100 at a negative angle θ₁ toform a sub-pixel 110. In the third vapor deposition operation 112 shownin FIG. 1D, a third type of material is deposited on the substrate 100vertically to form a sub-pixel 114. As shown in FIG. 1E, a metal layer116 is formed by the fourth vapor deposition operation 118 at an angleθ₂. Utilizing the vertical shadow mask 102, the interconnection betweensub-pixels is prevented. Although this method is able to produce afull-color display device, in fact, a few problems remain. The problemsinclude:

[0021] (I) The process of forming a vertical shadow mask: Since a wetphoto-resist production or a dielectric film deposition method is usedto form the shadow mask, thickness of the mask 102 can hardly rise above20 μm. In addition, forming a mask having uniform thickness on alarge-area substrate is difficult. If thickness of the mask layer isnon-uniform, subsequent positioning and size of red, green and bluesub-pixels are all affected.

[0022] (II) Shadow effect: The design of most conventional evaporatorfor deposition organic electro-luminescent material requires thesubstrate to be fastened onto a rotary holder. When the depositionstarts, the substrate rotates so that a uniform layer is formed.However, the substrate must be fixed in position in the shadow-maskprocess, so that a material beam can shine on the substrate at a fixedangle. Consequently, rotary deposition is not suitable for theshadow-mask process. Although any non-uniformity of the vapor-depositedlayer on a substrate when the substrate doesn't rotate can be reduced bycalibration, a non-rotating substrate renders every point on thesubstrate having a slightly different angle relative to a vaporizingsource. This can lead to variations in position and size of red, green,blue sub-pixels on the substrate. This phenomenon is all the moreserious when the substrate has a large surface area.

[0023] (III) Leakage current in the device: As shown in FIG. 1E, only alayer of organic film is deposited over the substrate at position 120 onthe right side of some shadow mask layer. This thinner portion canresult in considerable leakage current when a metal layer issubsequently deposited to serve as an electrode. This is also an areawhere short-circuiting is more likely to occur leading to devicefailure.

[0024] A conventional evaporator for vapor deposition has independentevaporation chambers. Indium-tin-oxide glass substrates are moved intodifferent evaporation chamber by robotic hands to perform differentvapor deposition processes. During the vapor deposition process, theindium-tin-oxide glass substrate must rotate continuously to form auniformly coated film. Hence, a conventional evaporator is unsuitablefor the shadow mask process. In addition, a convention evaporatoroperates on a unit-by-unit basis rather than a continuous productionflow. Therefore, spatial utilization of the evaporation chamber is low.Furthermore, size of the evaporation chamber limits the ultimate size ofthe indium-tin-oxide glass substrate. To achieve higher stability in theproduction process, sophisticated robotic control system has to bedeployed. This also adds to the production cost of an evaporator.

SUMMARY OF THE INVENTION

[0025] Accordingly, one object of the present invention is to provide amethod of manufacturing a high-efficiency full-color organicelectro-luminescent device with the direct full-color display technique.

[0026] A second object of this invention is to provide a method ofmanufacturing a full-color organic electro-luminescent device capable ofself-positioning red, blue and green sub-pixels on a substrateconcurrently so that the alignment steps in the traditional metal maskprocess are saved.

[0027] A third object of this invention is to provide a method ofmanufacturing a full-color organic electro-luminescent device thatemploys a unique insulation pad capable of preventing shadow effect thatmay lead to a leakage current in the device. Hence, production yield ofthe device is increased.

[0028] A fourth object of this invention is to provide a processingstation design that facilitates the manufacturing of the full-colororganic electro-luminescent device of this invention.

[0029] To achieve these and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, theinvention provides a method of manufacturing a full-color organicelectro-luminescent device. An indium-tin-oxide glass substrate isprovided. The indium-tin-oxide glass substrate is etched to form adesired pattern. The glass substrate is cleaned. An insulation pad isformed over the glass substrate by carrying out a photo-resistprocessing and a film-deposited operation. A patterned shadow mask isformed on the glass substrate by performing a dry film photo-resistprocessing. The shadow mask pattern can be subdivided into two types.One type of shadow mask has a thickness of about 1 μm to 10 μm, commonlyreferred to as a low shadow mask (LSM). Another type of shadow mask hasa thickness of about 5 μm to 100 μm, commonly referred to as a highshadow mask (HSM). The indium-tin-oxide glass substrate is cleanedagain. Hole-transport material such as N,N′-diphenyl-N,N′-(m-tolyl)benzidine (TPD) is deposited onto the indium-tin-oxide glass substratein a vapor-depositing process to form a uniform layer having a thicknessof about 30 nm to 100 nm. Preferably, the conducting material forms alayer having a thickness between 40 nm to 80 nm.

[0030] Blue light-emitting material used in the concurrentvapor-deposition process includes perylene. The blue light-emittingmaterial is deposited vertically onto the indium-tin-oxide glasssubstrate in the vapor-deposition process to form a uniform layerbetween 10 nm to 40 nm. Preferably, the deposited blue material has athickness between 15 nm to 30 nm. Red light-emitting material includingnile red and green light-emitting material including quinacridone arepreferably evaporated from each side at an suitable anglesimultaneously. The concentrations of the red and the greenlight-emitting materials are controlled to within 0.1% to 10% (v/v) involume ratio and preferably between 0.5% to 5%(v/v). After thevapor-deposition process, the blue sub-pixels are formed in the centerof the pixels while the red and the green sub-pixels are positioned oneach side of the blue sub-pixel. In the subsequent step,electron-transport material such as tris-(8-hydroxyquinoline) aluminum(Alq3) is deposited in a vapor-depositing process to form a uniformlayer with a thickness of about 30 nm to 100 nm. Preferably, thethickness is between 40 nm to 80 nm. magnesium (Mg) and silver (Ag) aredeposited with a tilted angle. The deposited metal functions as anegative electrode. The deposited magnesium layer has a thicknessbetween 10 nm to 100 nm, preferably between 30 nm to 70 nm. Thedeposited silver layer has a thickness between 150 nm to 500 nm,preferably between 200 nm to 350 nm. With the indium-tin-oxide layerfunctioning as a positive electrode and the metal layer as a negativeelectrode, a functional full-color organic electro-luminescent devicecould be performed when a suitable operating voltage is applied.

[0031] This invention also provides a processing station formanufacturing the full-color organic electro-luminescent device.

[0032] In this invention, the shadow mask is formed by a dry filmphoto-resist processing. In addition, RGB sub-pixels are positionedindividually by a slant-angle depositing process so that RGB sub-pixelscan be produced in a single vapor-depositing operation. Compared withthe conventional metal-mask-shift method, in which RGB sub-pixels aredeposited in three depositing operations, the invention has fewerprocessing steps and does not require accurate mask alignment, precisionshifting and mask cleaning. In brief, RGB positioning process of thisinvention is simple to operate and has a fast throughput, and hencesuitable for mass production at a lower cost.

[0033] The manufacturing station for producing electro-luminescentdevice of this invention also employs an innovative design. Rather thanrotating the indium-tin-oxide glass substrate while performing avapor-depositing operation, the glass substrate is mounted on a cassetteand carried by a conveyer belt to various vapor-depositing compartmentsfor different-type depositing operations. Consequently, themanufacturing station is capable of continuous processing, therebyincreasing overall spatial utilization. In addition, glass substratehaving a relatively large surface area can still be vapor-deposited bythe station. Since the glass substrate is moved by a conveyer beltsystem, robotic arm transport is unnecessary. Hence, cost of equipmentis reduced and processing stability is also improved.

[0034] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary, andare intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings,

[0036]FIGS. 1A through 1E are schematic cross-sectional views showingthe steps for producing a full-color organic electro-luminescent deviceaccording to a Kodak's patent;

[0037]FIG. 2 is a schematic side view showing the layout of variouscomponents of a processing station for manufacturing a full-colororganic electro-luminescent device of this invention;

[0038]FIG. 3 is a schematic top view of a 6×6 pixel array passive drivendisplay board according to one preferred embodiment of this invention;and

[0039]FIGS. 4A through 4G are schematic cross-sectional views showingthe progression of steps for forming a full-color organicelectro-luminescent device according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

[0041]FIG. 2 is a schematic side view showing a layout of components inthe processing station. The station includes a conveyer belt 200 (notshown in FIG. 2) for moving indium-tin-oxide glass substrates, cassettes202 and a plurality of evaporation source packs 204. Each evaporationsource pack 204 includes at least one evaporation source. Theseevaporation source packs are able to deposit a hole-transport layer,concurrent to deposit red, green and blue sub-pixels, then anelectron-transport layer and a metal layer. After a patterned shadowmask is formed over the indium-tin-oxide glass substrate 212 by dry filmphoto-resist processing, the indium-tin-oxide glass substrate 212 isplaced in a cassette 202 and put into area (I) of FIG. 2. The glasssubstrate 212 in the cassette 202 is carried by the moving conveyer belt200 into area (II) where the evaporation source pack 204 targets theglass substrate 212 to form a hole-transport layer. The glass substrate212 then moves on into area (III) where the evaporation source pack 204targets the glass substrate 212 to form red, green and blue sub-pixels.The glass substrate 212 is moved to area (IV) where the evaporationsource pack 204 targets the glass substrate 212 to form anelectron-transport layer. Finally, the glass substrate 212 moves to area(V) where the evaporation source pack 204 targets the glass substrate212 to form a metal layer. The evaporation sources in an evaporationsource pack 204 are positioned next to each other. Each evaporationsource pack 204 can carry out vapor-deposition operation independent ofothers. During the vapor-deposition process, the indium-tin-oxide glasssubstrate 212 remains stationary inside the cassette. Hence, no rotarymotion is imparted on the glass substrate 212. As shown in FIG. 2, theglass substrate 212 in the cassette 202 is deposited each time onpassing in front of a rectangular opening 214. Thickness of thevapor-deposited film depends on the parameters including depositionrate, width of the opening 216, moving speed, locations of theevaporation sources. These parameters are free to vary in eachvapor-depositing chamber so that deposition operations can be optimizedwith identical processing period. Consequently, each evaporation sourcegroup can carry out a different glass substrate depositing operationconcurrently. Uniformity of a deposited layer on the glass substrate 212in the vertical direction (vertical to the paper, not shown) of theopening 214 depends on the positioning of the evaporation sources andthe uniformity of deposition rate along the vertical direction.Uniformity of deposited layer can be improved by calibrating a group ofevaporation sources. The advantages of the vapor-depositing station ofthis invention over a conventional vapor-depositing station are listedout in Table 1 for comparison. In Table 1, the symbol “O” represents“best”, the symbols “Δ” represent “moderate” and the symbol “X”represents “worst”. TABLE 1 A comparison of the vapor-depositing stationin the invention with a coventional vapor-depositing station Vapor-Conventional vapor- depositing station acc- depositing station ording tothe invention Suitability for shadow- X O mask process Flexibility ofprocess- X O ing adjustments Suitability for deposit- Δ O ingdifferent-size substrate Spatial Utilization Δ O Stability Δ O Cost ofthe Station High Low

[0042] Compared with the indirect full-color methods such as TDK's whitelight with color filter, Idemitsu Kosan's and Kodak's blue light withcolor conversion medium and direct full-color method such as an stackeddevice, the full-color display technique used in this invention is adirect type, the full-color device fabricated according to thisinvention has a relatively higher emission efficiency and lower powerconsumption. Thus, the device is advantageous in portable electronicproducts such as mobile phone, personal data assistance (PDA) anddigital camera (DC).

[0043] Red, green and blue sub-pixels in the full-color organicelectro-luminescent device of this invention are positioned on thesubstrate in the same vapor-depositing operation. In addition, aninnovative dynamic manufacturing station having a continuous line ofvapor-depositing compartments is adopted for producing devices.Therefore, the method and the manufacturing station of this inventioncan be used together for the production of passive matrix well as activematrix in a full-color organic electro-luminescent display panel. FIG. 3is a schematic top view of a 6×6 passive matrix display according to onepreferred embodiment of this invention. As shown in FIG. 3, the displayboard 300 can be made of glass or plastic. Area labeled 302 shows anindium-tin-oxide material pattern. Area labeled 304 shows the connectingleads on the indium-tin-oxide panel for connecting with externalcircuits.

[0044]FIGS. 4A through 4G are schematic cross-sectional views showingthe progression of steps for forming a full-color organicelectro-luminescent device according to this invention. FIG. 4A is across-sectional view along line IV-IV′ of FIG. 3. FIG. 4B is a magnifiedview of the central portion of the substrate shown in FIG. 4A to show asingle pixel.

[0045] As shown in FIG. 4B, the substrate 400 can be made from glass orplastic. Traditional photolithography and etching process are carriedout to form a desired indium-tin-oxide pattern 404. Insulation pads 406are formed over the pattern 404 using photo-resist material and physicvapor depositing processes. The insulator pad 406, preferably having athickness of between 5 nm to 200 nm, can be a silicon oxide layer or asilicon nitride layer. The insulation pad 206 serves two functions,including the prevention of any current leaks from any thinner sectionof the organic film layer and defining the size of light-emitting regionso that pixel size is standardized. Finally, two dry film photo-resistprocessing operations are conducted to form two different types (havingdifferent height or thickness) of shadow masks over the insulation pads206. The first type of shadow mask has a height (or thickness) between 1μm to 10 μm, commonly referred to as a low shadow mask (LSM) 408. Thesecond type of shadow mask has a height (or thickness) between 5 μm to100 μm, commonly referred to as a high shadow mask (HSM) 410.

[0046] After the patterned shadow masks are formed over theindium-tin-oxide glass substrate 212 by dry film photo-resistprocessing, the indium-tin-oxide glass substrate 212 is placed inside acassette 202 and put into area (I) of FIG. 2. The cassette 202 servesnot only as a transportation carrier for the glass substrate 212, butserves also as mask preventing any vapor from depositing on electrodesnear the edges of the substrate 212. As shown in FIG. 4C, vapordeposition of hole-transport material 412 on the surface of theindium-tin-oxide glass substrate 212 to form a hole-transport layer 414is carried out in area (II) of FIG. 2. The glass substrate 212 in thecassette 202 is carried by a moving conveyer belt 200 into area (II). Anevaporation source pack 204 targets the glass substrate 212 and depositshole-transport material vertically on the substrate 212 to form thehole-transport layer 414. The rate of deposition of hole-transportmaterial is around 1 Å to 3 Å per second.

[0047] As shown in FIG. 4D, the high shadow mask 410 on the substrate212 is capable of positioning red sub-pixels 416, green sub-pixels 418and blue sub-pixels 420. Blue light-emitting material can be ahole-transport or an electron-transport material. Blue light-emittingmaterial 420 is deposited vertically onto the surface of theindium-tin-oxide glass substrate 212. On the other hand, redlight-emitting material 422 and green light-emitting material 424 aredeposited at an angle with the surface of the glass substrate 212. Theevaporators for the red and the green light-emitting material aremounted on each side of the evaporator for blue light-emitting materialwith the vapor beams at an angle θ_(R) and θ_(G) respectively. Ingeneral, the angles θ_(R) and θ_(G) are within the range from 45° to80°. Utilizing the shadowing effect of the high shadow mask 410,vapor-depositing operations are carried out concurrently. Red and greenlight-emitting materials are deposited on the right and left side of apixel position to form a red and a green sub-pixel. Blue light-emittingmaterial is deposited in the middle of the pixel position to form a bluesub-pixel. The percentages of the red and the green light-emittingmaterials in the blue light-emitting materials are about 0.5% to 5% byvolume ratio. Consequently, the film thickness in the co-deposition stepis mainly controlled by blue light-emitting material. The depositionrate of blue light-emitting material is around 1 to 3 Å/s while the rateof deposition of red and green-energy-gap material is around 0.01 to 0.3Å/s. The deposition of red, green and blue light-emitting materials iscarried out in area (III) of FIG. 2. The indium-tin-oxide glasssubstrate 212 is transported by the conveyer belt 200 into area (III).Utilizing the shadowing effect of the high shadow mask 410, red, greenand blue sub-pixels 416, 418 and 420 are concurrently formed on thepre-defined positions.

[0048] As shown in FIG. 2, the indium-tin-oxide glass substrate 212 ismoved by the conveyer belt 200 to area (IV). An evaporation source pack204 for electron-transport material targets the glass substrate 212 toform an electron-transport layer 428. As shown in FIG. 4E, anelectron-transport material 426 front lands on the surface of theindium-tin-oxide glass substrate 212 to form the electron-transportlayer 428. Deposition rate of the electron-transport material is around1 Å to 3 Å per second.

[0049] As shown in FIG. 2, the indium-tin-oxide glass substrate 212 ismoved by the conveyer belt 200 into area (V). An evaporation source pack204 for metal material targets the glass substrate at a suitable angleto form a metal electrode 432. As shown in FIG. 4F, metal material 430is deposited onto the surface of the glass substrate 212 at an angleθ_(M) from the vertical to form the metal electrode 432. The angle θ_(M)ranges from 5° to 60°. The materials as metal electrode could becalcium, magnesium, lithium, aluminum, silver and so on. Due to theshadowing effect of the high shadow mask 410 and the low shadow mask408, the metal electrodes 432 on the substrate 212 will be automaticallyisolated from each other. Hence, a full-color device containing aplurality of pixels with each pixel comprising of red and greensub-pixels on each side of a blue sub-pixel is formed.

[0050] During the vapor-depositing process as shown in FIG. 2, theindium-tin-oxide glass substrate 212 remains stationary inside thecassette 202. Hence, no rotary motion is imparted on the glass substrate212. As shown in FIG. 2, the glass substrate 212 in the cassette 202 isdeposited each time on passing in front of a rectangular opening 214.Thickness of the vapor-deposited film depends on parameters includingdeposition rate, width of the opening 216, moving speed, locations ofthe evaporation sources. These parameters are free to vary in eachvapor-depositing chamber to optimize each depositing operation so thateach operation is complete within identical period. Consequently, eachevaporation source group can carry out a different glass substratedepositing operation concurrently. Uniformity of a deposited layer onthe glass substrate 212 in the vertical direction (vertical to thepaper, not shown) of the opening 214 depends on the positioning of theevaporation sources 204 and the uniformity of deposition rate along thevertical direction. Uniformity of deposited layer can be improved bycalibrating a group of evaporation sources.

[0051] It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A method of manufacturing a full-color organicelectro-luminescent device, comprising the steps of: patterning anindium-tin-oxide glass substrate; cleaning the indium-tin-oxide glasssubstrate; forming an insulation pad over the indium-tin-oxide glasssubstrate; forming a low shadow mask over the insulation pad by thefirst dry film photo-resist process; forming a high shadow mask over theinsulation pad by conducting the second dry film photo-resist process;forming a hole-transport layer over the indium-tin-oxide glass substrateby conducting a vapor-depositing process; conducting threevapor-depositing processes simultaneously to form the red, the green andthe blue light-emitting materials on the hole-transport layer in thesame step using the low shadow mask and the high shadow mask as abarrier; forming an electron-transport layer over the red, the green andthe blue light-emitting materials by conducting a vapor-depositingprocess; and forming a metal layer over the electron-transport materialby conducting a vapor-depositing process.
 2. The method of claim 1,wherein material forming the insulation pad is selected from the groupconsisting of silicon nitride and silicon oxide.
 3. The method of claim1, wherein the low shadow mask has a thickness between 1 μm to 10 μm. 4.The method of claim 1, wherein the high shadow mask has a thicknessbetween 5 μm to 100 μm.
 5. The method of claim 1, wherein materialforming the hole-transport layer includes N,N′-diphenyl-N,N′-(m-tolyl)benzidine.
 6. The method of claim 1, wherein the hole-transport layerhas a thickness between 40 nm to 80 nm.
 7. The method of claim 1,wherein the blue vapor-depositing material used in the simultaneousvapor-depositing process includes perylene.
 8. The method of claim 1,wherein the thickness of the red, the green and the blue light-emittingmaterials is between 15 nm to 30 nm.
 9. The method of claim 1, whereinthe step of performing a simultaneous vapor-depositing process includesproviding a blue-light-emitting-material evaporation source, ared-light-emitting-material evaporation source and agreen-light-emitting-material evaporation source.
 10. The method ofclaim 1, wherein material forming the red sub-pixels includes nile redand material forming the green sub-pixels includes quinacridone.
 11. Themethod of claim 9, wherein the evaporation sources for the red and thegreen sub-pixels are positioned on each side of the blue materialevaporation source.
 12. The method of claim 9, wherein the step offorming the blue sub-pixels includes aiming a beam of blue material fromthe blue evaporation source front at the surface of the indium-tin-oxideglass substrate in a vapor-depositing process.
 13. The method of claim9, wherein the step of forming the red sub-pixels and the greensub-pixels includes aiming a beam of red material from the redevaporation source and a beam of green material from the greenevaporation source simultaneously at the indium-tin-oxide glasssubstrate surface both tilted at an identical angle from the verticalbut on opposite side.
 14. The method of claim 11, wherein the angle oftilt from the vertical is between 45° to 80°.
 15. The method of claim11, wherein the red and the green light-emitting materials in the bluelight-emitting material are controlled at a percentage between 0.5% to5% by volume ratio.
 16. The method of claim 1, wherein material formingthe electron-transport layer includes tris-(8-hydroxyquinoline)aluminum.
 17. The method of claim 1, wherein the electron-transportlayer has a thickness between 40 nm to 80 nm.
 18. The method of claim 1,wherein the evaporation source for depositing metal layer is set at anangle of tilt from a vertical to the indium-tin-oxide glass substratesurface.
 19. The method of claim 18, wherein the angle of tilt isbetween 5° to 60°.
 20. The method of claim 1, wherein material formingthe metal layer is selected from the group consisting of calcium,magnesium, lithium, aluminum and silver.
 21. The method of claim 1,wherein the metal layers include a layer of magnesium and a layer ofsilver.
 22. The method of claim 21, wherein the magnesium layer has athickness between 30 nm to 70 nm.
 23. The method of claim 21, whereinthe silver layer has a thickness between 200 nm to 350 nm.
 24. Themethod of claim 1, wherein the metal layer is a negative electrode. 25.The method of claim 1, wherein the indium-tin-oxide glass substrate is apositive electrode.
 26. The method of claim 1, wherein the insulationpad has a thickness between 5 μm to 200 μm.
 27. A processing station formanufacturing a full-color organic electro-luminescent device,comprising: a plurality of evaporation source packs with eachevaporation source pack having at least one evaporation source, whereineach evaporation source pack can be used for vapor-depositing varioustypes of materials; a plurality of cassettes with each cassette capableof holding one indium-tin-oxide glass substrate; and a conveyer belt formoving the cassettes that hold indium-tin-oxide glass substratecontinuously in such a way that each cassette passes in front of eachevaporation source pack sequentially to carry out the requiredvapor-depositing processes.